[PATCH v6 1/6] Documentation: dts: Documentation entry to explain how to use PWM FAN as a cooling device

Lukasz Majewski
2015-02-26T13:59:32Z

Explanation of several properties, which allow PWM fan working as a cooling
device, have been embraced in this commit.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Acked-by: Eduardo Valentin <edubezval@gmail.com>
---
Changes for v2:
- Rename cooling-pwm-values to cooling-levels
- Remove default-pulse-width property and stick to default hwmon policy
Changes for v3:
- Changing commit title from "hwmon: dts: Doc:" to "Documentation: dts"
- Remove unnecessary properties
- Set maximal cooling level to 230 instead of 255
Changes for v4:
- None
Changes for v5:
- Move thermal-zones description to example section
- Extending example section
Changes for v6:
- cooling-{min|max}-state properties added to pwm-fan binding
- Mandatory properties for thermal-zones added
- Indentation fixed
---
.../devicetree/bindings/hwmon/pwm-fan.txt | 29 ++++++++++++++++++++--
1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
index 610757c..c6d5332 100644
--- a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
+++ b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt
@@ -3,10 +3,35 @@ Bindings for a fan connected to the PWM lines
Required properties:
- compatible : "pwm-fan"
- pwms : the PWM that is used to control the PWM fan
+- cooling-levels : PWM duty cycle values in a range from 0 to 255
+ which correspond to thermal cooling states

Example:
- pwm-fan {
+ fan0: pwm-fan {
compatible = "pwm-fan";
- status = "okay";
+ cooling-min-state = <0>;
+ cooling-max-state = <3>;
+ #cooling-cells = <2>;
pwms = <&pwm 0 10000 0>;
+ cooling-levels = <0 102 170 230>;
};
+
+ thermal-zones {
+ cpu_thermal: cpu-thermal {
+ thermal-sensors = <&tmu 0>;
+ polling-delay-passive = <0>;
+ polling-delay = <0>;
+ trips {
+ cpu_alert1: cpu-alert1 {
+ temperature = <100000>; /* millicelsius */
+ hysteresis = <2000>; /* millicelsius */
+ type = "passive";
+ };
+ };
+ cooling-maps {
+ map0 {
+ trip = <&cpu_alert1>;
+ cooling-device = <&fan0 0 1>;
+ };
+ };
+ };
--
2.0.0.rc2